JP2005272612A - Optical film and image-displaying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film having excellent heat resistance allowing various kinds of functional layers to be formed at high temperature, and optical characteristics; and to provide an image-displaying device obtained by using the optical film and having excellent displaying quality. <P>SOLUTION: The optical film is composed of a polyarylate having a repeating unit represented by general formula (1) [wherein, X is a 1-20C divalent hydrocarbon group; A is a linking group represented by general formula (2) (wherein, ring Q<SP>1</SP>is a heterocycle containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom; R<SP>1</SP>and R<SP>2</SP>are each independently a hydrogen atom or a substituent; and j and k are each an integer of 1-4)]. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical film having excellent heat resistance and optical properties. Furthermore, the present invention relates to an image display device using the optical film and having excellent display quality.

  In recent years, in the field of flat panel displays such as liquid crystal display elements and organic electroluminescence elements (hereinafter referred to as “organic EL elements”), the substrate is replaced from glass to plastic in order to improve breakage resistance, reduce weight, and reduce thickness. Is being considered. In particular, there is a strong demand for a plastic substrate in a display device for mobile information communication equipment such as a portable information terminal such as a mobile phone, an electronic notebook, or a laptop personal computer.

  The plastic substrate needs to have conductivity. Therefore, in recent years, on a plastic film, a semiconductor film such as an oxide of indium oxide, tin oxide, or tin-indium alloy, a metal film such as an oxide film of gold, silver, or palladium alloy, or the semiconductor film and the metal film Research has been made on the use of a transparent conductive substrate having a transparent conductive layer in combination with the above as an electrode substrate of a display element.

  As the transparent conductive substrate used for this purpose, a heat-resistant amorphous polymer, for example, modified polycarbonate (modified PC) (for example, see Patent Document 1), polyethersulfone (PES) (for example, see Patent Document 2). In addition, a laminate in which a transparent conductive layer and further a gas barrier layer are laminated on a plastic film made of a cycloolefin copolymer (see, for example, Patent Document 3) is known.

  However, when the above heat-resistant plastic film was used, a plastic substrate having sufficient heat resistance could not be obtained. That is, when a conductive layer is formed on the plastic substrate using these heat-resistant plastic films as a substrate and then exposed to a temperature of 150 ° C. or higher for providing an alignment film, the conductivity and gas barrier properties are greatly reduced. was there.

Further, in recent years, a higher level of heat resistance is required for a base film in the case where a TFT for manufacturing an active matrix image element is installed. For example, Patent Document 4 describes a method for forming a polycrystalline silicon film at a temperature of 290 ° C. or lower by plasma decomposition of a gas containing SiH ₄ . Patent Document 5 describes a method for forming a semiconductor layer in which amorphous silicon and polycrystalline silicon are mixed on a polymer substrate at a temperature of 290 ° C. or less by irradiation with an energy beam. Patent Document 6 describes a method of providing a thermal buffer layer and irradiating a pulsed laser beam to form a polycrystalline silicon semiconductor layer on a plastic substrate at a temperature of 250 ° C. or lower.

  As shown in Patent Documents 4 to 6, various methods for forming a TFT polycrystalline silicon film at 290 ° C. or lower have been proposed. However, the configuration and apparatus are complicated and expensive, and in practice, Heat resistance of 250 ° C. or higher is required for plastic substrates.

On the other hand, several polyarylate materials having heat resistance have been developed so far. For example, Non-Patent Document 1 describes highly heat-resistant polyarylate derived from phenolphthalein, phenolphthalimidine, phenolisatin, phenolsulfonephthalein and divalent carboxylic acid. Patent Document 7 describes a polyester for optical materials composed of phenolphthalein and a divalent carboxylic acid. Patent Document 8 describes a polyarylate derived from phenolphthalein and an aromatic divalent carboxylic acid as a gas diaphragm. Patent Document 9 describes that polyarylate derived from isatin bisphenol and isatin biscresol is used for a heat-resistant protective lubricating layer in a thermal transfer recording sheet.
However, none of these documents describes that the heat-resistant polyarylate is applied to an optical film, particularly an optical film for an image display device.
JP 2000-227603 A (Claim 7, [0009] to [0019]) JP 2000-284717 A ([0010], [0021] to [0027]) JP 2001-150584 A ([0027] to [0039]) JP-A-7-81919 (Claim 3, [0016] to [0020]) JP 10-512104 A (pages 14-22, FIGS. 1 and 7) JP-A-11-102867 (Claims 1 to 10, [0036]) JP-A-62-2292830 (Claims) JP-A-4-227828 (Claims) JP 2000-79768 A (Claims) Journal of Polymer Science: Part A, 2, 437-459 (1964)

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical film having both excellent heat resistance and optical properties capable of installing various functional layers at high temperatures.
Still another object of the present invention is to provide an image display device using the optical film and having excellent display quality.

  As a result of intensive studies on the structure of polyarylate to achieve the above object, the present inventors have found that a polyarylate having a predetermined structure can form a film capable of achieving both heat resistance and optical properties. I found it. Furthermore, even when this film was used for an image display element, it was confirmed that it exhibited sufficient heat resistance, and the present invention was completed.

That is, the object of the present invention is achieved by the following means.
(1) An optical film comprising polyarylate having a repeating unit represented by the following general formula (1).

  In general formula (1), X is a C1-C20 bivalent hydrocarbon group, and may have a substituent. A represents a linking group represented by the following general formula (2).

In general formula (2), ring Q ¹ represents a heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and may have a substituent. R ¹ and R ² each independently represents a hydrogen atom or a substituent. j and k each represent an integer of 1 to 4. When j and / or k is an integer of 2 or more, R ¹ and / or R ² may be the same or different.
(2) X in the general formula (1) is a divalent hydrocarbon group having 6 to 20 carbon atoms which may have a substituent containing one or more aromatic rings, and A represents the following general formula ( The optical film according to (1), which is a linking group represented by 3).

In general formula (3), ring Q ² represents a heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom. R ¹ , R ² and R ³ each independently represent a hydrogen atom, alkyl group, aryl group, halogen atom, alkoxy group, acyl group, cyano group, nitro group, heterocyclic group or condensed ring, j, k And l represents an integer of 1 to 4. When j, k and / or l is an integer of 2 or more, R ¹ , R ² and / or R ³ may be the same or different.
(3) The optical film according to (1) or (2), wherein X in the general formula (1) is a kind selected from the group consisting of the following structural formulas.

(4) The optical film according to any one of (1) to (3), comprising polyarylate having a plurality of repeating units represented by the general formula (1).
(5) The optical film according to any one of (1) to (4), wherein the glass transition temperature of the polyarylate having the repeating unit represented by the general formula (1) is 250 ° C. or higher.
(6) The optical film according to any one of (1) to (5), wherein the total light transmittance is 80% or more.
(7) The optical film according to any one of (1) to (6), wherein a gas barrier layer is laminated on at least one surface.
(8) The optical film according to any one of (1) to (7), wherein a transparent conductive layer is laminated on at least one surface.

  Another object of the present invention is achieved by an image display device using the optical film described in any one of (1) to (8) above.

  The optical film of the present invention comprises polyarylate having a predetermined repeating unit. Thereby, according to this invention, while having the outstanding heat resistance, the optical film which has the outstanding optical characteristic can be provided.

  The image display element of the present invention uses the optical film. Thereby, according to this invention, the image display element which shows the outstanding optical characteristic in liquid surface display, an organic EL element, etc. can be provided.

Hereinafter, the optical film of the present invention and an image display element using the optical film will be described in detail.
In the present specification, “to” is used as a meaning including numerical values described before and after the lower limit value and the upper limit value.

[Optical film]
The optical film of the present invention is an optical film containing a polyarylate having a repeating unit represented by the following general formula (1) (hereinafter also referred to as “polyarylate of the present invention”).
Hereinafter, the polyarylate of the present invention will be described.

  The polyarylate of the present invention has a repeating unit represented by the following general formula (1).

  In General Formula (1), X is a C1-C20, Preferably it is C2-C18, More preferably, it is a C2-C12 bivalent hydrocarbon group, and may have a substituent. Further, X is a divalent hydrocarbon group having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, and more preferably 6 to 12 carbon atoms, which may have a substituent containing one or more aromatic rings. Desirably, it is more desirable to be one selected from the group consisting of the following structural formulas.

    X is more preferably one type selected from the group consisting of the following structural formulas.

  In the polyarylate of the present invention, A in the general formula (1) has a linking group represented by the following general formula (2).

In general formula (2), ring Q ¹ is a heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, preferably a 4 to 8 membered ring, more preferably a 5 to 7 membered member. A ring, more preferably a 5- to 6-membered heterocyclic ring. Ring Q ¹ may have a substituent, and the substituent is not particularly limited. For example, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (eg, methyl Group, ethyl group), aryl group (for example, phenyl group, naphthyl group), alkenyl group, alkynyl group, cyano group, carboxyl group, alkoxycarbonyl group (for example, methoxycarbonyl group), aryloxycarbonyl group (for example, phenoxycarbonyl) Group), substituted or unsubstituted carbamoyl group (for example, carbamoyl group, N-phenylcarbamoyl group, N, N-dimethylcarbamoyl group), alkylcarbonyl group (for example, acetyl group), arylcarbonyl group (for example, benzoyl group) Nitro group, acylamino group (for example, acetamide group, eth Cicarbonylamino group), sulfonamide group (for example, methanesulfonamide group), imide group (for example, succinimide group, phthalimide group), imino group (for example, benzylideneamino group), alkoxy group (for example, methoxy group), aryl Oxy group (eg, phenoxy group), acyloxy group (eg, acetoxy group), alkylsulfonyloxy group (eg, methanesulfonyloxy group), arylsulfonyloxy group (eg, benzenesulfonyloxy group), sulfo group, substituted or Unsubstituted sulfamoyl group (for example, sulfamoyl group, N-phenylsulfamoyl group), alkylthio group (for example, methylthio group), arylthio group (for example, phenylthio group), alkylsulfonyl group (for example, methanesulfonyl group), aryl A sulfonyl group (for example, benzenesulfonyl group), a heterocyclic ring, etc. can be mentioned.

Moreover, the substituent of the ring Q ¹ may be further substituted, and when there are a plurality of substituents, each substituent may be the same or different. The substituent may form a condensed ring with the ring Q ¹ . As a substituent, a halogen atom, alkyl group, aryl group, cyano group, alkylcarbonyl group, arylcarbonyl group, nitro group, acylamino group, sulfonamide group, imide group, alkoxy group, aryloxy group, sulfo group, alkyl A sulfonyl group, an arylsulfonyl group, and a heterocyclic group, more preferably a halogen atom, an alkyl group, an aryl group, a cyano group, an alkylcarbonyl group, an arylcarbonyl group, a nitro group, an alkoxy group, an aryloxy group, and a heterocyclic group And more preferably a halogen atom, an alkyl group, or an aryl group. It is also preferred that the substituent forms a condensed ring with a heterocyclic ring consisting of ring Q ₁ , and a benzo condensed ring is particularly preferred.

R ¹ and R ² each represent an independent hydrogen atom or substituent. The substituent is not particularly limited, but those listed as the substituent for ring Q ¹ can be applied, and preferred examples are also the same. j and k are integers of 1 to 4, preferably 1 or 2. When j and / or k is 2 or more, R ¹ and / or R ² may be the same or different. Preferably, R ¹ and R ² are the same.

  The general formula (2) is preferably represented by the general formula (3).

In the general formula (3), the ring Q ² is a nitrogen atom, represent a heterocyclic ring containing at least one atom selected from oxygen atom and sulfur atom, preferably 4-8 membered rings, more preferably 5- to 7-membered A ring, more preferably a 5- to 6-membered heterocyclic ring. Ring Q ² may have a substituent, and the substituent is not particularly limited, but those listed as the substituent of ring Q ^{1 in} the general formula (2) can be applied, and preferred examples are also the same.

In the general formula (3), R ¹ , R ² and R ³ are each independently a hydrogen atom or a substituent, and the substituent is not particularly limited, but an alkyl group, aryl group, halogen atom, alkoxy group, acyl It is preferably a group, a cyano group, a nitro group, a heterocyclic group or a condensed ring. J, k and l are integers of 1 to 4, preferably 1 or 2. When j, k and / or l is an integer of 2 or more, R ¹ , R ² and / or R ³ may be the same or different, and preferably R ¹ , R ² and R ³ are This is the case.

  Although the preferable example of the coupling group represented by the said General formula (2) is shown below in the form of bisphenol, this invention is not limited to this.

  Among the preferable examples of the linking group represented by the general formula (2) shown in the form of bisphenol, those having a benzo-condensed 5-membered heterocyclic ring from the viewpoint of heat resistance (for example, A-1, A -5, A-15, A-31, A-35) are more preferable.

  Commercially available bisphenol compounds can be used, and methods known in the art (for example, Journal of Polymer Science, Part A, Volume 2, pages 437-459 (1964), Synthetic Communication, Volume 29 No. 19, pages 3303 to 3311 (1999)).

  The polyarylate having a repeating unit represented by the general formula (1) can be obtained by polycondensation of the bisphenol compound and a divalent carboxylic acid. From the viewpoint of heat resistance and transparency, the general formula (1) It is preferable to have a plurality of repeating units represented by Moreover, you may copolymerize various well-known bisphenol compounds in the range which does not impair heat resistance and transparency.

  In the present invention, when the molar percentage of the repeating structural unit represented by the general formula (1) in the polyarylate is i, 50 ≦ i ≦ 100 mol% is preferable, and 60 ≦ i ≦ 100 mol%. More preferably, it is more preferable that 80 ≦ i ≦ 100 mol%.

  Hereinafter, although the preferable example of the polyarylate which has a repeating unit represented by General formula (1) is shown with a bisphenol and a dicarboxylic acid unit, this invention is not limited to this. The bisphenol compounds exemplified above are represented by their numbers, 2,6-naphthalenedicarboxylic acid is represented as X-1, 4,4′-biphenyldicarboxylic acid is represented as X-2, terephthalic acid is represented as T, Isophthalic acid is represented as I. Moreover, when using a some compound, each molar ratio is also written down.

Next, the manufacturing method of the polyarylate of this invention is demonstrated.
The polyarylate having the repeating unit represented by the general formula (1) can be obtained by polycondensation of the corresponding bisphenol compound and dicarboxylic acid. The polycondensation method includes a melt polycondensation method by deacetic acid, a melt polycondensation method by dephenol, a dehydrochloric acid homogeneous polymerization method in which an organic base is used as a dicarboxylic acid compound as an acid chloride and the polymer is soluble, Any known method such as an interfacial polycondensation method using a dicarboxylic acid compound as an acid chloride in a two-phase system of an alkaline aqueous solution and a water-immiscible organic solvent can be used. However, when the glass transition temperature (Tg) of polyarylate is 250 ° C. or higher, melt polycondensation becomes difficult. However, as described in JP-A-7-188405, a high-boiling plasticizer is used in combination. Thus, the polymerization can be carried out even at a reaction temperature of about 250 ° C.

When synthesizing the polyarylate of the present invention, it is convenient and preferable to use an interfacial polycondensation method. However, a typical known interfacial polycondensation method, as represented by the method using bisphenol A, terephthalic acid, and isophthalic acid, makes the bisphenol compound soluble in an alkaline aqueous solution and makes the dicarboxylic acid chloride immiscible with water. A method is adopted in which the solution is made soluble in an organic solvent (typically dichloromethane or the like) and these solutions are mixed in a short time.
In the present invention, the solubility of the bisphenol compound in an alkaline aqueous solution may be low. In addition, 2,6-naphthalenedicarboxylic acid chloride has low solubility in water-immiscible organic solvents, and it may not be possible to synthesize polyarylate having a repeating unit represented by the general formula (1) having a high molecular weight by a known method. is there. In this case, water, water-immiscible organic solvent, bisphenol compound, dicarboxylic acid chloride are mixed and stirred in a slurry state, and a high-concentration alkaline aqueous solution is gradually added to increase the molecular weight. is there.

  The molecular weight of the polyarylate of the present invention can be adjusted by adding a monofunctional substance at the time of polymerization regardless of the above production method. Monofunctional substances used as molecular weight regulators include monohydric phenols such as phenol, cresol, p-tert-butylphenol, monovalent acid chlorides such as benzoic acid chloride, methanesulfonyl chloride, and phenyl chloroformate, methanol, Monovalent alcohols such as ethanol, n-propanol, isopropanol, n-butanol, pentanol, hexanol, dodecyl alcohol, stearyl alcohol, benzyl alcohol, phenethyl alcohol, acetic acid, propionic acid, octanoic acid, cyclohexanecarboxylic acid, benzoic acid , Monovalent carboxylic acids such as toluic acid, phenyl acid, p-tert-butylbenzoic acid and p-methoxyphenylacetic acid.

  The preferred molecular weight of the polyarylate of the present invention is 10,000 to 500,000 in terms of weight average molecular weight, preferably 20,000 to 300,000, and more preferably 30,000 to 200,000. If the molecular weight is at least 10,000, film forming is possible and good mechanical properties can be obtained. On the other hand, if the molecular weight is 500,000 or less, the molecular weight can be controlled in the synthesis, and an appropriate solution viscosity can be obtained and it is easy to handle. The molecular weight can be based on the corresponding viscosity.

  The carboxyl value of the polyarylate of the present invention is preferably 300 μmol / g or less, more preferably 30 μmol / g or less, and particularly preferably 10 μmol / g or less. If the carboxyl value is 300 μmmol / g or less, it is difficult to affect the electrical properties such as arc discharge resistance and dielectric constant and the storage stability of the polymer solution prepared by dissolving in a solvent, and the cast film obtained by the solution casting method This is preferable because it does not easily affect the surface characteristics. The carboxyl value of polyarylate can be measured by a known method such as neutralization titration using a potentiometric titrator.

  The amount of residual alkali metal and halogen in the polyarylate of the present invention is preferably 50 ppm or less, and particularly preferably 10 ppm or less. If the residual alkali metal content and halogen content were 50 ppm or less, the electrical properties were not deteriorated, and further good surface properties of the film were obtained, and a functional film formed with a conductive film, a semiconductor film, etc. was produced. In some cases, good performance is preferable. The amount of residual alkali metal and halogen in the polyarylate of the present invention can be quantified using known methods such as ion chromatography analysis, atomic absorption spectrometry, and plasma emission spectrometry.

  The amount of the catalyst such as quaternary ammonium salt and quaternary phosphonium salt remaining in the polyarylate of the present invention is preferably less than 200 ppm, more preferably less than 100 ppm. If the amount of catalyst remaining is 200 ppm or less, the above-described good electrical characteristics and film surface characteristics can be obtained, and good performance can be obtained when a functional film having a conductive film, a semiconductor film, etc. is produced. It is easy and preferable. Catalysts such as quaternary ammonium salts and quaternary phosphonium salts remaining in the polyarylate of the present invention can be quantified using HPLC, gas chromatography, or the like.

The amount of the phenol monomer and dicarboxylic acid remaining in the polyarylate of the present invention is preferably 3000 ppm or less, more preferably 500 ppm or less, and even more preferably 100 ppm. If the amount of residual phenol monomer and carboxylic acid is 3000 ppm or less, the above-mentioned good electrical characteristics and surface characteristics of the film can be obtained, and it is good when a functional film formed with a conductive film, a semiconductor film, etc. is produced. Performance is obtained. More specifically, for example, when forming a transparent conductive film on the film, due to the influence of heating and plasma during film formation, etc., to generate a gas such as residual phenol monomer or carboxylic acid component, Due to thermal decomposition, crystal grains are formed in the transparent conductive film, or an uncoated part called “missing” is generated, and the low resistance of the transparent conductive film is hindered. However, in the present invention, since the amount of residual phenol monomer and dicarboxylic acid is 3000 ppm or less, there is no such disadvantage.
The amount of phenol monomer and dicarboxylic acid remaining in the polyarylate and the film can be analyzed by a known method such as HPLC or nuclear magnetic resonance.

Although the synthesis example of the polyarylate of this invention is shown below, the polyarylate of this invention is not limited to these.
(Synthesis Example 1) Synthesis of Exemplary Compound P-4 Exemplary Compound A-1 (phenolphthalein: manufactured by Tokyo Chemical Industry Co., Ltd.) 6.37 g (20 mmol), tetrabutylammonium chloride 278 mg (1.0 mmol), hydrosulfite soda 60 mg (0.34 mmol), 38 ml of dichloromethane and 75 ml of water were put into a reaction vessel equipped with a stirrer and stirred at 300 rpm in a water bath under a nitrogen stream. After 10 minutes, a solution of 2.03 g (10 mmol) of terephthalic acid chloride and 2.03 g (10 mmol) of isophthalic acid chloride in 53 ml of dichloromethane, a solution of 21 ml of 2M (2N) sodium hydroxide aqueous solution diluted with 4 ml of water, Were simultaneously dropped using a dropping apparatus over 1 hour, and after completion of the reaction, each was washed with 10 ml of dichloromethane and 10 ml of water. Thereafter, stirring was continued for 3 hours, and then 25 ml of dichloromethane was added to separate the organic phase. Further, the organic phase was washed with a dilute hydrochloric acid aqueous solution, and further washed twice with 100 ml of water. To the separated organic phase, 30 ml of dichloromethane was added, diluted, and then poured into 1.5 L of methanol that was vigorously stirred over 1 hour. The resulting white precipitate in methanol was collected by filtration, dried by heating at 40 ° C. for 12 hours, and then dried under reduced pressure at 70 ° C. for 3 hours to obtain 7.60 g of Exemplified Compound P-4.
As a result of measuring the molecular weight of the obtained P-4 with GPC (THF solvent), the weight average molecular weight was 52,000. Moreover, the glass transition point measured by DSC was 297 degreeC.

(Synthesis Example 2) Synthesis of Exemplary Compound P-11 Exemplary Compound A-15 (Naphtholphthalein: Wako Pure Chemical Industries, Ltd.) 8.37 g (20 mmol), tetrabutylammonium chloride 278 mg (1.0 mmol), hydrosulfite soda 60 mg (0.34 mmol), dichloromethane 38 ml, and water 75 ml were put into a reaction vessel equipped with a stirrer, and stirred in a water bath at 300 rpm in a nitrogen stream. Ten minutes later, a solution prepared by dissolving 2.03 g (10 mmol) of terephthalic acid chloride and 2.03 g (10 mmol) of isophthalic acid chloride in 53 ml of dichloromethane and a solution obtained by diluting 21 ml of 2M (2N) aqueous sodium hydroxide solution with 4 ml of water. Were simultaneously dropped using a dropping apparatus over 1 hour, and after completion of the reaction, each was washed with 10 ml of dichloromethane and 10 ml of water. Thereafter, stirring was continued for 3 hours, and then 25 ml of dichloromethane was added to separate the organic phase. Further, the organic phase was washed with a dilute hydrochloric acid aqueous solution, and further washed twice with 100 ml of water. To the separated organic phase, 30 ml of dichloromethane was added, diluted, and then poured into 1.5 L of methanol that was vigorously stirred over 1 hour. The resulting white precipitate in methanol was collected by filtration, dried by heating at 40 ° C. for 12 hours, and then dried under reduced pressure at 70 ° C. for 3 hours to obtain 8.85 g of Exemplified Compound P-11.
As a result of measuring the molecular weight of the obtained P-11 by GPC (THF solvent), the weight average molecular weight was 35,000. The glass transition point measured by DSC was 310 ° C.

(Synthesis Example 3) Synthesis of Exemplified Compound P-15 Exemplified Compound A-35 (1-methylisatin: manufactured by Aldrich) 6.63 g (20 mmol), tetrabutylammonium chloride 278 mg (1.0 mmol), hydrosulfite soda 60 mg ( 0.34 mmol), 38 ml of dichloromethane and 75 ml of water were put into a reaction vessel equipped with a stirrer, and stirred at 300 rpm in a water bath under a nitrogen stream. Ten minutes later, a solution prepared by dissolving 2.03 g (10 mmol) of terephthalic acid chloride and 2.03 g (10 mmol) of isophthalic acid chloride in 53 ml of dichloromethane and a solution obtained by diluting 21 ml of 2M (2N) aqueous sodium hydroxide solution with 4 ml of water. Were simultaneously dropped using a dropping apparatus over 1 hour, and after completion of the reaction, each was washed with 10 ml of dichloromethane and 10 ml of water. Thereafter, stirring was continued for 5 hours, and then 25 ml of dichloromethane was added to separate the organic phase. Further, the organic phase was washed with a dilute hydrochloric acid aqueous solution, and further washed twice with 100 ml of water. To the separated organic phase, 30 ml of dichloromethane was added, diluted, and then poured into 1.5 L of methanol that was vigorously stirred over 1 hour. The resulting white precipitate in methanol was collected by filtration, dried by heating at 40 ° C. for 12 hours, and then dried at 70 ° C. under reduced pressure for 3 hours to obtain 7.20 g of Exemplified Compound P-15.
As a result of measuring the molecular weight of the obtained P-15 with GPC (THF solvent), the weight average molecular weight was 85,000. The glass transition point measured by DSC was 292 ° C.

Next, the film made of the polyarylate of the present invention will be described.
As a method for forming the polyarylate of the present invention into a film or sheet shape, a known method can be adopted, but a solution casting method is preferably used. Regarding the casting and drying methods in the solution casting method, US Pat. No. 2,336,310, US Pat. No. 2,367,603, US Pat. No. 2,429,078, US Pat. No. 2,429,297, US Pat. No. 2,492,978, US Pat. No. 2739070, British Patent No. 640731, British Patent No. 736892, Japanese Examined Patent Publication No. 45-4554, Japanese Examined Patent Publication No. 49-5614, Japanese Unexamined Patent Publication No. 60-176634, Japanese Unexamined Patent Publication No. 60-203430, Japanese Unexamined Patent Publication No. There is description in each gazette of 62-1115035. Examples of the manufacturing apparatus manufactured by the solution casting method include the manufacturing apparatus described in Japanese Patent Laid-Open No. 2002-189126, paragraphs [0061] to [0068], FIG. 1 and FIG. The invention is not limited to these examples.

  In the solution casting method, the polyarylate of the present invention is dissolved in a solvent. Any solvent may be used as long as it dissolves the polyarylate of the present invention, but it is particularly preferable to use a solvent that can dissolve at a solid content concentration of 10% by mass or more at 25 ° C. Further, the boiling point of the solvent used is preferably 200 ° C. or lower, more preferably 150 ° C. or lower. A boiling point of 200 ° C. or lower is preferable because the solvent can be sufficiently dried and easily removed from the film. In addition, a poor solvent can be mixed as long as the solubility of the polyarylate of the present invention is not impaired. In this case, it may be advantageous from the viewpoint of stripping after the solution casting and drying speed.

  Examples of the solvent used in the present invention include methylene chloride, chloroform, tetrahydrofuran, 1,4-dioxane, benzene, cyclohexane, toluene, xylene, anisole, γ-butyrolactone, benzyl alcohol, isophorone, cyclohexanone, cyclopentanone, 1 , 2-dichloroethane, 1,1,2,2-tetrachloroethane, ethyl acetate, acetone, chlorobenzene, dichlorobenzene, dimethylformamide, methanol, ethanol and the like, but the present invention is not limited thereto. In addition, two or more solvents may be used as a mixture, and a mixed solvent is preferable from the viewpoint of achieving both dryness and solubility. Moreover, by using a mixed solvent, the transparency of the optical film of the present invention may be improved, which is preferable.

  The polyarylate concentration in the solution used for solution casting is 5 to 60% by mass, preferably 10 to 40% by mass, and more preferably 10 to 30% by mass. When the polyarylate concentration is 5% by mass or more, an appropriate viscosity can be maintained and the thickness can be easily adjusted. On the other hand, when the polyarylate concentration is 60% by mass or less, the film can be formed satisfactorily and unevenness can be reduced. Moreover, the transmittance | permeability of the optical film of this invention and the impurity in a film can be reduced by filtering as needed before solution casting.

  The method for casting the solution is not particularly limited, but it can be cast on a flat plate or a roll using a bar coater, a T die, a T die with a bar, a doctor blade, a roll coat, a die coat or the like.

  The temperature at which the solvent is dried varies depending on the boiling point of the solvent used, but it is preferable to dry the solvent in two stages. Thereby, a polyarylate film having optical isotropy can be obtained. As a first step, drying is performed at 30 to 100 ° C. until the solvent concentration is 10% by mass or less, more preferably 5% by mass or less. Next, as a second step, the film is peeled off from the flat plate or roll and dried in the range of 60 ° C. or higher and the glass transition temperature of the resin or lower. When the film is peeled off from the flat plate or the roll, it may be peeled off immediately after completion of the drying in the first stage or may be peeled off after being cooled once.

  The optical film of the present invention has a large amount of residual solvent if heat drying is insufficient, and if it is excessively heated, it causes thermal decomposition of polyarylate and increases the amount of residual phenol monomer. Furthermore, rapid drying by heating causes rapid vaporization of the contained solvent, and causes defects such as bubbles in the film.

The amount of the solvent remaining in the optical film of the present invention is preferably 2000 ppm or less, more preferably 1000 ppm or less, and further preferably 100 ppm or less. If the amount of solvent remaining in the film is 2000 ppm or less, the characteristics of the film surface will be deteriorated, the surface treatment will not be adversely affected, and the performance of the functional film provided with a conductive film, a semiconductor film, etc. will deteriorate. It does not cause.
The amount of the solvent remaining in the polyarylate film of the present invention can be quantified using a known method such as gas chromatography.

  The optical film of the present invention is preferably a method in which a solution is cast on a rotating drum or a band, peeled off, and dried continuously to be wound into a roll. Thus, when the optical film of this invention is conveyed mechanically, it is preferable that the mechanical strength of a film is high. The preferred mechanical strength depends on the conveying device and cannot be generally specified, but as a guide, the breaking stress and breaking elongation obtained from the tensile test of the film can be used. A preferable breaking stress is 50 MPa or more, more preferably 80 MPa or more, and further preferably 100 MPa or more. The elongation at break varies depending on the sample preparation conditions and the like, but is preferably 5% or more, more preferably 10% or more, and further preferably 15% or more.

  The optical film of the present invention may be stretched. By stretching, mechanical strength such as folding strength is improved, and there is an advantage that handling property is improved. In particular, those having an orientation release stress (ASTMD1504, hereinafter abbreviated as ORS) in the stretching direction of 0.3 to 3 GPa are preferred because the mechanical strength is improved. The ORS is an internal stress generated by stretching inherent in the stretched film or sheet.

  Although a known method can be used for stretching, when the polyarylate of the present invention has a Tg of 250 ° C. or higher, it is difficult to stretch only by heating, and therefore it can be stretched in a state containing a solvent. In this case, it is preferable to perform stretching in the course of drying. For example, a roll uniaxial stretching method, a tenter uniaxial stretching method, and a simultaneous temperature at a temperature between 10 ° C. and 50 ° C. higher than the Tg containing the solvent. The film can be stretched by a biaxial stretching method, a sequential biaxial stretching method, or an inflation method. The draw ratio is 1.1 to 3.5 times, preferably 1.1 to 2.0 times.

  The polyarylate of the present invention may be only one type or two or more types may be mixed. In addition, a polymer other than the polyarylate of the present invention may be contained within a range that does not impair the effect of the present invention (1 to 50% by mass, preferably 1 to 20% by mass). Moreover, you may add crosslinked resin from viewpoints, such as solvent resistance, heat resistance, and mechanical strength.

  As the cross-linked resin, various known ones can be used without particular limitation for both the thermosetting resin and the radiation curable resin. Examples of the thermosetting resin include phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, diallyl phthalate resin, furan resin, bismaleimide resin, cyanate resin and the like. The crosslinking method can be used without particular limitation as long as it is a reaction that forms a covalent bond, and the method in which the reaction proceeds at room temperature using a polyalcohol compound and a polyisocyanate compound to form a urethane bond is also particularly limited. Can be used without However, in such a method, the pot life before film formation often becomes a problem, and is usually used as a two-component mixed type in which a polyisocyanate compound is added immediately before film formation.

  Further, when used as a one-pack type, it is effective to protect functional groups involved in the crosslinking reaction, and it is also commercially available as a block type curing agent. As commercially available block type curing agents, B-882N manufactured by Mitsui Takeda Chemical Co., Ltd., Coronate 2513 manufactured by Nippon Polyurethane Industry Co., Ltd. (above block polyisocyanate), Cymel 303 manufactured by Mitsui Cytec Co., Ltd. (methylated melamine resin) ) Etc. are known. Further, a blocked carboxylic acid such as the following B-1 that protects a polycarboxylic acid that can be used as a curing agent for an epoxy resin is also known.

  Radiation curable resins are roughly classified into radical curable resins and cationic curable resins. As the curable component of the radical curable resin, a compound having a plurality of radical polymerizable groups in the molecule is used. As a typical example, a polyfunctional acrylate having 2 to 6 acrylate groups in the molecule A compound called a monomer or a compound having a plurality of acrylate groups in a molecule called urethane acrylate, polyester acrylate, or epoxy acrylate is used.

  As a typical curing method of the radical curable resin, there are a method of irradiating an electron beam and a method of irradiating ultraviolet rays. Usually, in the method of irradiating with ultraviolet rays, a polymerization initiator that generates radicals upon irradiation with ultraviolet rays is added. In addition, if the polymerization initiator which generate | occur | produces a radical by heating is added, it can also be used as a thermosetting resin. As the curable component of the cationic curable resin, a compound having a plurality of cationic polymerizable groups in the molecule is used. As a typical curing method, a photoacid generator that generates an acid upon irradiation with ultraviolet rays is added, and ultraviolet rays are added. And a method of curing by irradiation. Examples of the cationically polymerizable compound include a compound containing a ring-opening polymerizable group such as an epoxy group and a compound containing a vinyl ether group.

  In the optical film of the present invention, a plurality of the above thermosetting resins and radiation curable resins may be mixed and used, or a thermosetting resin and a radiation curable resin may be used in combination. Moreover, you may mix and use a crosslinkable resin and the polymer which does not have a crosslinkable group.

  Furthermore, it is also possible to introduce a crosslinkable group into the polyarylate of the present invention used in the optical film of the present invention, and it has a crosslinkable group at any of the polymer main chain terminal, polymer side chain and polymer main chain. It may be. In this case, it can bridge | crosslink without using the general purpose crosslinkable resin mentioned above together.

  The optical film of the present invention may contain a metal oxide and / or a metal complex oxide and a metal oxide obtained by a sol-gel reaction. In this case, heat resistance and solvent resistance can be imparted in the same manner as the above-mentioned crosslinked resins. Furthermore, resin modifiers such as plasticizers, dyes / pigments, antistatic agents, ultraviolet absorbers, antioxidants, inorganic fine particles, peeling accelerators, leveling agents, and lubricants as long as the effects of the present invention are not impaired as necessary. May be added.

  The thickness of the optical film of the present invention is not particularly defined, but is preferably 30 to 700 μm, more preferably 40 to 200 μm, and further preferably 50 to 150 μm. Further, the haze of the optical film of the present invention is preferably 3% or less, more preferably 2% or less, and further preferably 1% or less. The total light transmittance of the optical film of the present invention is preferably 70% or more, more preferably 80% or more, and further preferably 85% or more.

The heat resistant temperature of the optical film of the present invention is preferably high, and Tg by DSC measurement can be used as a guide. In this case, the preferable Tg of the optical film of the present invention is 250 ° C. or higher, more preferably 300 ° C. or higher, and particularly preferably 330 ° C. or higher.
In addition, when the optical film of the present invention is produced by the solution casting method using only the polyarylate of the present invention, if the drying is sufficient, there is almost no difference between the Tg of the polyarylate used and the Tg of the optical film, Within measurement error range.

  The surface of the optical film of the present invention is subjected to treatment such as saponification, corona treatment, flame treatment, glow discharge treatment, etc. on the film substrate surface in order to enhance the adhesion with other layers or components depending on the application. Can do. Furthermore, an adhesive layer and an anchor layer may be provided on the film surface. Depending on the purpose, smoothing layer for surface smoothing, hard coat layer for imparting scratch resistance, ultraviolet absorbing layer for enhancing light resistance, surface roughening layer for improving film transportability, etc. Various known functional layers can be provided.

  The optical film of the present invention can form a transparent conductive layer. As the transparent conductive layer, known metal films, metal oxide films, and the like can be applied. Among these, metal oxide films are preferable from the viewpoint of transparency, conductivity, and mechanical properties. For example, metal oxide films such as indium oxide, cadmium oxide and tin oxide to which tin, tellurium, cadmium, molybdenum, tungsten, fluorine, zinc, germanium, etc. are added as impurities, zinc oxide, titanium oxide, etc. to which aluminum is added as impurities, Can be mentioned. Among them, an indium oxide thin film mainly composed of tin oxide and containing 2 to 15% by mass of zinc oxide is excellent in transparency and conductivity, and is preferably used.

  The transparent conductive layer can be formed by any method as long as the target thin film can be formed. For example, the material can be formed from the gas phase such as sputtering, vacuum deposition, ion plating, and plasma CVD. A vapor phase deposition method in which a film is deposited to form a film is suitable. For example, the film can be formed by the methods described in Japanese Patent No. 3434344, Japanese Patent Laid-Open No. 2002-322561, and Japanese Patent Laid-Open No. 2002-361774. . Especially, it is preferable to use sputtering method from a viewpoint that the outstanding electroconductivity and transparency are acquired.

  The preferred degree of vacuum of the sputtering method, vacuum deposition method, ion plating method, and plasma CVD method is 0.133 mPa to 6.65 Pa, more preferably 0.665 mPa to 1.33 Pa. Before providing such a transparent conductive layer, it is preferable to subject the base film to a surface treatment such as plasma treatment (reverse sputtering) or corona treatment. Moreover, you may heat up to 50-200 degreeC during providing the transparent conductive layer.

  The film thickness of the transparent conductive layer obtained by the above method is preferably 20 to 500 nm, and more preferably 50 to 300 nm.

  Moreover, it is preferable that the surface electrical resistance measured by 25 degreeC60% RH (relative humidity) of the transparent conductive layer obtained by said method is 0.1-200 ohm / square, and 0.1-100 ohm / square. It is more preferable that it is 0.5-60Ω / □. The light transmittance of the transparent conductive layer is preferably 80% or more, more preferably 83% or more, and further preferably 85% or more.

  The optical film of the present invention is preferably provided with a gas barrier layer in order to suppress gas permeability. Preferred gas barrier layers include, for example, metal oxides composed mainly of one or more metals selected from the group consisting of silicon, aluminum, magnesium, zinc, zirconium, titanium, yttrium, and tantalum, silicon, aluminum, boron And a gas barrier layer made of a metal nitride or a mixture thereof. Above all, silicon oxide whose ratio of the number of oxygen atoms to the number of silicon atoms is 1.5 to 2.0 is the main component from the viewpoint of gas barrier properties, transparency, surface smoothness, flexibility, film stress, cost, etc. The metal oxide layer is good.

  The gas barrier layer made of the inorganic compound can be produced by a vapor deposition method in which a film is formed by depositing a material from the vapor phase, such as sputtering, vacuum deposition, ion plating, or plasma CVD. Among these, it is preferable to use a sputtering method from the viewpoint of obtaining particularly excellent gas barrier properties. Further, the temperature may be raised to 50 to 200 ° C. while the gas barrier layer is provided.

  The film thickness of the gas barrier layer obtained by the above method is preferably 10 to 300 nm, and more preferably 30 to 200 nm.

  The gas barrier layer may be provided on the same side as the transparent conductive layer or on the opposite side, but is preferably provided on the opposite side.

Gas barrier of the optical film having a gas barrier layer is preferably a water vapor permeability as measured at 40 ° C. 90% RH is less than 5g / m ² · day, more preferably at most 1g / m ² · day, More preferably, it is 0.5 g / m ² · day or less. The oxygen permeability was measured at 40 ° C. 90% RH is preferably not more than ^{1ml / m 2 · day · atm} , more preferably not more than ^{0.7ml / m 2 · day · atm} , 0.5ml More preferably, it is not more than / m ² · day · atm. When the gas barrier performance is within the above range, for example, when used in an organic EL or LCD, it is preferable that deterioration of the EL element due to water vapor and oxygen can be substantially eliminated.

  In order to improve the gas barrier performance, it is preferable to form a defect compensation layer adjacent to the gas barrier layer. As the defect compensation layer, for example, (1) an inorganic oxide layer produced by using a sol-gel method as described in US Pat. No. 6,171,663 and Japanese Patent Application Laid-Open No. 2003-94572, (2) US Pat. The organic layer described in the specification, No. 64163645 can be used. These defect compensation layers can be produced by vapor deposition under vacuum and then curing by ultraviolet rays or electron beams, or by applying and then curing by heating, electron beams, ultraviolet rays or the like. When the defect compensation layer is produced by a coating method, various conventional coating methods such as spray coating, spin coating, and bar coating can be used.

[Image display device]
The optical film of the present invention can be used as a substrate for a thin film transistor (TFT) display element. As a method for manufacturing the TFT array, for example, a method described in JP-T-10-512104 can be used. Further, these substrates may have a color filter for color display. The color filter may be manufactured using any method, but is preferably manufactured using a photolithography technique.

  The optical film of the present invention can be used in an image display device after providing various functional layers as necessary. Here, it does not specifically limit as an image display apparatus, A conventionally well-known thing can be used. Moreover, the flat panel display excellent in display quality can be produced using the optical film of this invention. Examples of the flat panel display include liquid crystal, plasma display, electroluminescence (EL), fluorescent display tube, light emitting diode, etc. In addition to these, it is used as a substrate in place of a glass substrate of a display system in which a conventional glass substrate has been used. be able to. Furthermore, the optical film of the present invention can also be used for applications such as solar cells and touch panels. The touch panel can be applied to those described in JP-A-5-127822, JP-A-2002-48913, and the like.

  When the optical film of the present invention is used for liquid crystal display applications, it is preferably an amorphous polymer in order to achieve optical uniformity. Further, it is preferable that the birefringence is small, and in particular, the in-plane retardation (Re) is preferably 50 nm or less, more preferably 30 nm or less, and further preferably 15 nm or less.

  In order to obtain an optical film having a small birefringence by using only the polyarylate of the present invention, it is possible to appropriately adjust the solvent and drying conditions during solution casting. Moreover, it can also extend | stretch and adjust as needed. Further, for the purpose of controlling retardation (Re) and its wavelength dispersion, resins having different intrinsic birefringence signs can be combined, or resins having a large (or small) wavelength dispersion can be combined. In addition, the optical film of the present invention can be suitably used for the purpose of controlling retardation (Re) and improving gas permeability and mechanical properties, etc. Further, phase difference compensation can be performed by using a known retardation plate in combination.

  The reflective liquid crystal display device includes, in order from the bottom, a lower substrate, a reflective electrode, a lower alignment film, a liquid crystal layer, an upper alignment film, a transparent electrode, an upper substrate, a λ / 4 plate, and a polarizing film. Of these, the optical film of the present invention may be used as a λ / 4 plate and a protective film for a polarizing film by adjusting optical properties, but is preferably used as a substrate from the viewpoint of heat resistance, and further from the viewpoint of transparency. It is preferable to use as a transparent electrode and an upper substrate with an alignment film. Moreover, a gas barrier layer, TFT, etc. can also be provided as needed. In the case of color display, it is preferable to further provide a color filter layer between the reflective electrode and the lower alignment film, or between the upper alignment film and the transparent electrode.

  The transmissive liquid crystal display device includes, in order from the bottom, a backlight, a polarizing plate, a λ / 4 plate, a lower transparent electrode, a lower alignment film, a liquid crystal layer, an upper alignment film, an upper transparent electrode, an upper substrate, a λ / 4 plate, and a polarization It consists of a membrane. Of these, the optical film of the present invention may be used as a λ / 4 plate or a polarizing film protective film by adjusting the optical properties, but is preferably used as a substrate from the viewpoint of its heat resistance, and has a transparent electrode and an alignment film attached. It is preferable to use it as a substrate. Moreover, a gas barrier layer, TFT, etc. can also be provided as needed. In the case of color display, it is preferable to further provide a color filter layer between the lower transparent electrode and the lower alignment film, or between the upper alignment film and the transparent electrode.

  The liquid crystal cell is not particularly limited, but TN (Twisted Nematic), IPS (In-P1ane Switching), FLC (Ferroelectric Liquid Crysta1), AFLC (Anti-ferroelectric Liquid Crystal), OCB (Optica1ly Compensatory Bend), STN (Supper Twisted Nematic) ), VA (Vertically Aligned) and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above display mode is oriented and divided has been proposed. The optical film of the present invention is effective in any display mode liquid crystal display device. Further, it is effective in any of a transmissive, reflective, and transflective liquid crystal display device.

  These are disclosed in JP-A-2-176625, JP-B-7-69536, MVA (SID97, Digest of tech. Papers (Preliminary Collection) 28 (1997) 845, SID99, Digest of tech. Papers (Preliminary Collection) 30 ( 1999) 206), JP-A-11-258605, SURVAIVAL (Monthly Display, Vol. 6, No. 3 (1999) 14), PVA (Asia Display 98, Proc. Of the-18th-Inter. Display res. Conf. (Preliminary Collection) (1998) 383), Para-A (LCD / PDP Iternational`99), DDVA (SID98, Digest of tech. Papers (Preliminary Collection) 29 (1998) 838), EOC (SID98, Digest of tech Papers 29 (1998) 319), PSHA (SID98, Digest of tech. Papers 29 (1998) 1081), RFFMH (Asia Display 98, Proc. Of the-18th-Inter. Display res Conf. (Preliminary Collection) (1998) 375), HMD (SID98, Digest of tech. Papers (Preliminary Collection) 29 (1998) 702), Japanese Patent Application Laid-Open No. 10-123478, International Publication No. W098 / 48320, Patent No. 3022477, O It is described in the fine International Publication WO00 / 65384 Patent Publication.

The optical film of the present invention is provided with a gas barrier layer and TFT as necessary, and can be used as a substrate with a transparent electrode for organic EL display applications.
As a specific layer structure as the organic EL display element, anode / light emitting layer / transparent cathode, anode / light emitting layer / electron transport layer / transparent cathode, anode / hole transport layer / light emitting layer / electron transport layer / transparent cathode , Anode / hole transport layer / light emitting layer / transparent cathode, anode / light emitting layer / electron transport layer / electron injection layer / transparent cathode, anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron Examples include injection layer / transparent cathode.

  The organic EL element in which the optical film of the present invention can be used applies a direct current (which may include an alternating current component as necessary) voltage (usually 2 to 40 volts) or a direct current between the anode and the cathode. Thus, light emission can be obtained.

  Regarding the driving of the light emitting element, for example, JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234585, JP-A-8- No. 241047, US Pat. Nos. 5,828,429 and 6023308, Japanese Patent No. 2784615, and the like can be used.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these.

The measuring method of the characteristic value of the optical film of the present invention is shown below.
<Weight average molecular weight>
It was obtained by GPC measurement using polystyrene as a solvent in comparison with a polystyrene molecular weight standard product (manufactured by Tosoh Corporation, HLC-8120GPC).
<Glass transition temperature (Tg)>
Measured by DSC (in nitrogen, temperature rising temperature 10 ° C./min) (Seiko Co., Ltd., DSC6200).
<Thickness of film>
It was measured with a dial-type thickness gauge (manufactured by Anritsu Co., Ltd., K402B).
<Total light transmittance of film>
It measured with the JASCO-made haze meter.
<Mechanical properties of film>
A film sample (1.0 cm × 5.0 cm piece) was prepared and measured with Tensilon (manufactured by Toyo Baldwin Co., Ltd., Tensilon RTM-25) under the condition of a tensile speed of 3 mm / min. Three samples were measured, and the average value was obtained (the sample was used after standing overnight at 25 ° C. and RH 60%. Distance between chucks: 3 cm).

Example 1 Production of Optical Film Samples (Samples 101 to 109) Polyarylate (BisA-I / T) Derived from Biaryphenol A and Isophthalic Acid / Terephthalic Acid (Equimolar) as Comparative Polymer of the Present Invention and Comparative Polymer Was dissolved at a concentration such that the solution viscosity after being dissolved in dichloromethane was in the range of 500 to 1500 mPa · s or less. The solution was filtered through a 5 μm filter and cast on a glass substrate using a doctor blade. After casting, the film was heat-dried at room temperature for 2 hours, at 80 ° C. for 2 hours, and at 100 ° C. for 4 hours, and then peeled off from the glass substrate to obtain an optical film sample.
The film thickness, total light transmittance, breaking stress, and breaking elongation of the obtained optical film sample were measured. The results are shown in Table 2 together with the molecular weight and Tg of the polymer used.

From Table 2, it can be seen that the optical films (samples 102 to 109) of the present invention all have a high glass transition temperature (Tg) and excellent heat resistance as compared with the comparative example (sample 101). Moreover, it turns out that the optical film of this invention is excellent in breaking stress compared with a comparative example.
This shows that the optical film of the present invention is a film excellent in heat resistance and durability.

[Example 2] Preparation of organic EL element samples 203, 205 and 208 <Formation of gas barrier layer>
By DC magnetron sputtering on both surfaces of the optical film samples 101,103,105,108 prepared in Example 1, under a vacuum of target the Si0 ₂ 500 Pa, an Ar atmosphere, and sputtering at an output 5 kW. The film thickness of the obtained gas barrier layer was 60 nm.

<Formation of transparent conductive layer>
While heating the optical film sample provided with the gas barrier layer to 100 ° C., ITO (In ₂ O ₃ 95% by mass, SnO ₂ 5% by mass) is used as a target, under a vacuum of 0.665 Pa by a DC magnetron sputtering method. A transparent conductive layer made of an ITO film having an output of 5 kW and a thickness of 140 nm was provided on one side in an Ar atmosphere.

<Heat treatment of optical film with transparent conductive layer>
The optical film sample on which the gas barrier layer and the transparent conductive layer were formed was subjected to heat treatment at 250 ° C. for 1 hour assuming TFT installation.

<Production of organic EL element>
From the transparent electrode layer of the heat-treated optical film sample, an aluminum lead wire was connected to form a laminated structure. In addition, the optical film sample on which the gas barrier layer and the transparent conductive layer obtained from the optical film sample 101 were formed was so deformed that an organic EL element could not be produced.
The surface of the transparent electrode was spin-coated with an aqueous dispersion of polyethylene dioxythiophene / polystyrene sulfonic acid (BAYER, Baytron P: solid content 1.3 mass%), and then vacuum-dried at 150 ° C. for 2 hours to obtain a thick A hole-transporting organic thin film layer having a thickness of 100 nm was formed. This was designated as substrate X.
On the other hand, a coating liquid for a light-emitting organic thin film layer having the following composition is applied on one side of a temporary support made of 188 μm thick polyethersulfone (Sumilite FS-1300 manufactured by Sumitomo Bakelite Co., Ltd.) using a spin coater. The luminescent organic thin film layer having a thickness of 13 nm was formed on the temporary support by applying and drying at room temperature. This was designated as transfer material Y.

Polyvinylcarbazole (Mw = 63000, manufactured by Aldrich): 40 parts by mass Tris (2-phenylpyridine) iridium complex (orthometalated complex): 1 part by mass Dichloroethane: 3200 parts by mass

  The luminescent organic thin film layer side of the transfer material Y is superimposed on the upper surface of the organic thin film layer of the substrate X, heated and pressurized at 160 ° C., 0.3 MPa, 0.05 m / min using a pair of heat rollers, By peeling off, a light-emitting organic thin film layer was formed on the upper surface of the substrate X. This was designated as substrate XY.

Further, a patterned evaporation mask (a mask having a light emission area of 5 mm × 5 mm) is formed on one side of a polyimide film (UPILEX-50S, manufactured by Ube Industries) having a thickness of 50 μm cut into a 25 mm square, and about 0. Al was evaporated in a reduced pressure atmosphere of 1 mPa to form an electrode having a film thickness of 0.3 μm. Using an Al ₂ O ₃ target by DC magnetron sputtering, the Al ₂ O ₃ was deposited in the same pattern as the Al layer and the thickness of 3 nm. Aluminum lead wires were connected from the Al electrode to form a laminated structure. A coating solution for an electron transporting organic thin film layer having the following composition is coated on the obtained laminated structure using a spin coater coating machine, and vacuum dried at 80 ° C. for 2 hours, thereby transporting an electron having a thickness of 15 nm. An organic thin film layer was formed on LiF. This was designated as substrate Z.

Polyvinyl butyral 2000L (Mw = 2000, manufactured by Denki Kagaku Kogyo Co., Ltd.): 10 parts by mass 1-butanol: 3500 parts by mass Electron transporting compound having the following structure: 20 parts by mass

  Using the substrates XY and Z, the electrodes are stacked so that the electrodes face each other with the light-emitting organic thin film layer interposed therebetween, and heated and pressurized at 160 ° C., 0.3 MPa, 0.05 m / min using a pair of heat rollers, The organic EL element samples 203, 205, and 208 were obtained by bonding.

  When the obtained organic EL element samples 203, 205 and 208 were applied to the organic EL element using a source measure unit 2400 type (manufactured by Toyo Technica Co., Ltd.), the samples 203, 205 and 208 of the present invention were used. Confirmed to emit light.

  From the above examples, it was revealed that the optical film of the present invention is halogen-free and excellent in heat resistance, transparency and mechanical properties. Moreover, it became clear that the optical film of this invention can laminate | stack functional layers, such as a gas barrier layer and a transparent conductive layer, and it functions as a substrate film for organic EL elements, even if it heat-processes supposing the TFT process.

  The optical film of the present invention may be used for an image display device such as a flat panel display such as a liquid crystal, a plasma display, an electroluminescence (EL), a fluorescent display tube, and a light emitting diode after providing various functional layers as necessary. it can. Moreover, the optical film of this invention can be utilized also for uses, such as a solar cell and a touch panel.

Claims (9)

An optical film comprising polyarylate having a repeating unit represented by the following general formula (1).

In general formula (1), X is a C1-C20 bivalent hydrocarbon group, and may have a substituent. A represents a linking group represented by the following general formula (2).

In general formula (2), ring Q ¹ represents a heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and may have a substituent. R ¹ and R ² each independently represents a hydrogen atom or a substituent. j and k each represent an integer of 1 to 4. When j and / or k is an integer of 2 or more, R ¹ and / or R ² may be the same or different. X in the general formula (1) is a divalent hydrocarbon group having 6 to 20 carbon atoms which may have a substituent containing one or more aromatic rings, and A is the following general formula (3) The optical film according to claim 1, which is a linking group represented.

In general formula (3), ring Q ² represents a heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom. R ¹ , R ² and R ³ each independently represent a hydrogen atom, alkyl group, aryl group, halogen atom, alkoxy group, acyl group, cyano group, nitro group, heterocyclic group or condensed ring, j, k And l represents an integer of 1 to 4. When j, k and / or l is an integer of 2 or more, R ¹ , R ² and / or R ³ may be the same or different. The optical film according to claim 1 or 2, wherein X in the general formula (1) is one selected from the group consisting of the following structural formulas.

The optical film as described in any one of Claims 1-3 which consists of polyarylate which has multiple types of repeating units represented by the said General formula (1). The optical film as described in any one of Claims 1-4 whose glass transition temperature of the polyarylate which has a repeating unit represented by the said General formula (1) is 250 degreeC or more. The optical film according to claim 1, having a total light transmittance of 80% or more. The optical film according to claim 1, wherein a gas barrier layer is laminated on at least one surface. The optical film according to any one of claims 1 to 7, wherein a transparent conductive layer is laminated on at least one surface. The image display apparatus using the optical film as described in any one of Claims 1-8.